After a protest organized by the Senior Action Network, San Francisco authorities announced they would step up enforcement of The City's ban on sidewalk cycling, which carries a $138 fine. Only children 12 years old and younger can legally ride their bikes on the sidewalk in San Francisco.

The Senior Action Network protested the presence of cyclists on sidewalks. "For years, pedestrians have been squeezed, shoved, intimidated and injured by bicyclists and motorists. The sidewalk is designated as a walkway, not a parking lot for cars or a bike lane for cyclists," said David Grant, executive director of Senior Action Network, which organized the event.

"Pedestrians in San Francisco have been killed and injured by bicyclists," said Michael Radetsky, injury-prevention coordinator for the San Francisco Department of Public Health. Since 2000, he said, there have been three reported deaths and more than 20 people injured badly enough to need hospitalization.

I've occasionally been guilty of this crime, but I totally understand the walkers' viewpoint. I've also been nearly plowed into by rude cyclists on busy sidewalks.